C5氯醇的合成研究

Synthesis of C5 Chlorohydrins

C5氯醇是合成维生素A醋酸酯的关键前体,经酯化(和转位)和氧化反应可制得合成维生素A醋酸酯的关键原料4-乙酰氧基-2-甲基-2-丁烯-1-醛。以亚氯酸钠与甲醛在酸性条件下原位反应提供次氯酸源,再与异戊二烯发生氯醇化反应,生成C5氯醇,避开直接使用稳定性差的次氯酸、腐蚀性较大的三氯异氰尿酸、环保不达标的四氯甘脲或二氯海因等,反应条件温和,反应易控,重现性好,具有工业化价值。

C5 chlorohydrin is the key precursor for the synthesis of vitamin A acetate.The key raw material 4-acetoxy-2-methyl-2-butene for the synthesis of vitamin A acetate can be obtained through esterification(and translocation)and oxidation reactions.Sodium chlorite reacts with formaldehyde in situ under acidic conditions to provide a source of hypochlorous acid,and then undergoes chlorohydrin reaction with isoprene to produce C5 chlorohydrins,avoiding direct use of hypochlorous acid with poor stability,trichloroisocyanuric acid with high corrosiveness,tetrachloroglycoluril or dichlorohydantoin which is not up to environmental standards,etc,the reaction conditions are mild,the reaction is easy to control,the reproducibility is good,and it has industrial value.